Bug 2372281 (CVE-2025-5986) - CVE-2025-5986 thunderbird: Unsolicited File Download, Disk Space Exhaustion, and Credential Leakage via mailbox:/// Links
Summary: CVE-2025-5986 thunderbird: Unsolicited File Download, Disk Space Exhaustion, ...
Keywords:
Status: NEW
Alias: CVE-2025-5986
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-06-11 12:47 UTC by OSIDB Bzimport
Modified: 2025-06-11 22:11 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2025-06-11 12:47:25 UTC
A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content.


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